KEB COMBIVERT F5, Reference Manual

Page: 104 / 349

For optimum control of the elevator, it is recommended to learn the system
inertia and activate the feed forward torque controller (FFTC).
FFTC reduces the dependence on the speed feedback from the motor
by predicting what the system will do and providing the required torque
command based on that prediction.
The first step in learning the system inertia is to get the car running at
contract speed over multiple floors.
The next step is to balance the car and run on inspection in the middle of
the hoist way and monitor the torque (Diag. screen #3). The motor torque in
the up and down directions should be equal but in the opposite direction. If
this is not the case, adjust the counterweights before proceeding.
For buildings with 12 floors or less, run the car from bottom to top and top
to bottom. For taller buildings, run between at least 10 floors in the middle
of the hoist way (5 above and 5 below). This function will also take into
account rope compensation or lack thereof. So, it is necessary to make this
measurement in the middle of the hoist way.
When ready, run the car between floors at high speed. High speed must be
reached! If it can’t, then lower the speed such that the car reaches a stable
speed for at least two seconds.
Begin the process by setting:
• LL10 - Inertia Learn to “Start”
Then follow the directions on the keypad. After each run, the user will have
the option to calculate the inertia for that run. After four runs, the drive will
automatically calculate the inertia based on the averages.
Note: During the Inertia Learn process, the drive reduces the
acceleration to a fixed rate (1.5 ft/sec^2). It may be necessary to adjust
any speed following or tach error settings in the controller to prevent
shutdowns.
5.12 Advanced Ride
Adjustments
5.12.1 Inertia Learn
i
104
Initial Startup